It was February when the problems started. Just north of Sacramento, nestled among outdoor recreation areas, the Oroville Dam started falling apart. The world’s tallest dam’s main spillway partially collapsed; dam managers started using an emergency spillway that sent water down a bare hillside, which quickly eroded. As 200,000 people were evacuated downstream with more rain on the way, a problem with dust probably wasn’t on the minds of the folks at the California Department of Water Resources (DWR).
But on March 16, the Los Angeles Times reported that air and soil analysis at the Oroville dam site, where debris was being removed, revealed one of the most dreaded airborne particulates out there: cancer-causing asbestos. Naturallyoccurring asbestos is not uncommon in California, but still, the state was obliged to produce dust-control measures, to protect workers at the site and residents in the area who may be affected. News releases from the dWR indicated that they were using water, at least at first, to keep the dust down. Methods included wetting the soil with water trucks and things like washing the trucks and truck tires on the vehicles used at the site.